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Sreedevi Meka, D Ankamma Rao. Role of HRCT in Smoking Related Interstitial Lung Diseases. IAIM, 2019; 6(8): 78-94.
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Original Research Article
Role of HRCT in Smoking Related
Interstitial Lung Diseases
Sreedevi Meka1*
, D Ankamma Rao2
1Senior Resident,
2Professor & HOD
Department of Radio Diagnosis, NRI Medical College & General Hospital, Chinakakani, Mangalagiri
Mandal, Guntur District, Andhra Pradesh, India *Corresponding author email: siri898@yahoo.co.in
International Archives of Integrated Medicine, Vol. 6, Issue 8, August, 2019.
Copy right © 2019, IAIM, All Rights Reserved.
Available online at http://iaimjournal.com/
ISSN: 2394-0026 (P) ISSN: 2394-0034 (O)
Received on: 26-07-2019 Accepted on: 09-08-2019
Source of support: Nil Conflict of interest: None declared.
How to cite this article: Sreedevi Meka, D Ankamma Rao. Role of HRCT in Smoking Related
Interstitial Lung Diseases. IAIM, 2019; 6(8): 78-94.
Abstract
Background: Smoking induced lung diseases constitute a complex group of disorders, varying from
the well-known entity of Chronic Obstructive Pulmonary Disease (COPD) to the more recently
described interstitial lung diseases.
Aim and objectives: The aim of the study was to delineate the relation between cigarette smoking
and the development of interstitial lung disease with declaration of the different types of the
interstitial lung associated with smoking.
Materials and methods: This was prospective study consisting of patients with smoking history
referred to Department of Radiodiagnosis of NRIGH for HRCT with symptoms of progressive
dyspnea. Inclusion criteria were smokers with progressive dyspnea, (age range 30-90 years, mean age
54 years ± 8). HRCT was done to all subjects using GE Light Speed Multislice 4 channels. CT scan
examination was performed using GE Light Speed Multislice 4 channels present in our radiology
department. The examination was done in supine position. A scout was taken with kV 120 and mA
120, then helical scanning was done in caudo-cranial direction to minimize respiration artifacts, using
detector row 4, helical thickness 1.25, pitch 1.5:1, speed (mm/rot) 7.5, Detector configuration 4 · 1.25,
beam collimation 5.00 mm, interval 1.00, gantry tilt 0.0, FOV depends on the patients’ body build, but
is about 35 cm, kV 120–140, mA 120–160, total exposure time about 16 s during breath hold in
inspiration. The images acquired were sent to a separate workstation to be processed, manipulated and
reconstructed. Reconstruction of the images was done using reconstruction software available at the
workstation to attain HRCT axial, coronal and sagittal images. Also mediastinal window images were
done for each case.
Results: In the present study, the most common seen HRCT pattern was Idiopathic Pulmonary
Fibrosis, most affected gender were males and most affected age group was between 60-70 years.
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Conclusion: In the appropriate clinical evaluation and in the presence of typical findings, high -
resolution CT plays an essential role in evaluation and definite diagnosis of Smoking Related –
Interstitial Lung Disease, and this may obviate further testing. However, lung biopsy may be needed
when the high-resolution CT are relatively non-specific or when a confident definitive diagnosis is
needed.
Key words
Respiratory Bronchiolitis, Desquamative Interstitial Pneumonia, Pulmonary Langerhans Cell
Histiocytosis, High Resolution Computed Tomography, Smoking Related Interstitial Lung Diseases.
Introduction
Smoking induced lung diseases constitute a
complex group of disorders, varying from the
well-known entity of Chronic Obstructive
Pulmonary Disease (COPD) to the more recently
described interstitial lung diseases (ILDs) [1, 2].
Development of interstitial lung disease is a
recognized risk factor for cigarette smoking [3].
Four Interstitial lung diseases (ILDs) have been
related to cigarette smoking: Respiratory
Bronchiolitis (RB)-associated ILD (RB-ILD),
Desquamative Interstitial Pneumonia (DIP),
Idiopathic Pulmonary Fibrosis (IPF) and
Pulmonary Langerhans Cell Histiocytosis
(PLCH) [4]. Among patients with these disorders
there is a prevalence of current or ex-smokers:
over 90% in RB-ILD, 60–90% in DIP and 41–
83% in IPF. Thus, cigarette smoking is to be a
risk factor of great significance.
Respiratory Bronchiolitis (RB) also called
‘‘smoker’s bronchiolitis,’’. Importantly, RB may
persist in some patients for many years after
stopping smoking [10]. The most common high-
resolution CT findings in RB-ILD are
centrilobular nodules, ground-glass opacities,
and thickening of the bronchial walls, which
predominate in the upper lobes. Upper lobe
emphysema is also commonly present.
Desquamative interstitial pneumonia (DIP) was
initially described by Liebow, et al. [12]. This
disease is characterized by the widespread
accumulation of intra-alveolar macrophages,
with usually mild interstitial reaction, although
some conditions may evolve to fibrosis and end-
stage lung disease. Currently, it is well known
that the histopathologic patterns of RB-ILD and
DIP may overlap, and the key feature to
differentiate both disorders is the distribution and
extent of the lesions: Bronchiolocentric in the
RB-ILD, or diffuse in the DIP [4]. It was
previously considered that DIP was the early,
cellular phase and UIP the later, fibrotic phase of
the same disease [19, 20], but they are now
accepted as separate clinical-pathologic entities.
The predominant abnormality at high-resolution
CT in patients with DIP is ground-glass opacity,
which may be peripheral, patchy, or diffuse in
distribution [2, 14]. A peripheral subpleural and
basal predominance of ground-glass opacity is
most commonly seen. Honeycombing is
uncommon. Coexistent emphysema may be
present. At follow-up high-resolution CT of
patients receiving treatment, the ground-glass
opacity may show partial or complete resolution
[15, 16].
Langerhans cell Histiocytosis refers to a group of
diseases of unknown etiology often recognized in
childhood, in which Langerhans cell
accumulations involve one or more body
systems, including bone, lung, pituitary gland,
mucous membranes, skin, lymph nodes, and
liver. This disease is also referred to as
Histiocytosis X or Eosinophilic Granuloma. The
term Pulmonary Langerhans Cell Histiocytosis
refers to disease in adults that affects the lung
[17]. The condition is uncommon, with a
prevalence of 3.4% in a series of 502 patients
undergoing surgical lung biopsy for chronic
diffuse infiltrative lung disease [18]. The peak
occurrence is at 20–40 years of age.
Approximately 25% of patients are
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asymptomatic, and the disease is uncovered on a
routine chest radiograph. In patients with PLCH,
typical findings on chest radio- graphs include
nodular or reticulonodular opacities most
prominent in the middle and upper lung zones
[19]. There is usually sparing of the costophrenic
angles and the lung volume appears normal or
increased. High-resolution CT is sensitive and
specific for the diagnosis of PLCH, the
characteristic finding being a combination of
nodules and cysts predominating in the upper and
mid lungs, sparing the bases. Early in the disease,
nodules with irregular borders predominate,
mainly in a peribronchiolar distribution. As the
disease evolves, thick- or thin-walled cysts
predominate and are often irregular. Longitudinal
studies with high-resolution CT show that the
solid nodules progress to cavitatory nodules, then
thick-walled cysts, and finally thin-walled cysts
[13].
A relationship between cigarette smoking and
Idiopathic Pulmonary Fibrosis has been
recognized for many years [6]. IPF is also called
cryptogenic fibrosing alveolitis in Europe [5]. A
high prevalence of current or former smokers is
noted in a series of IPF patients, varying from
41% to 83% [5]. Recent work suggests that
smoking may have a detrimental effect on IPF
with survival and severity-adjusted survival
being higher in nonsmokers than in former
smokers or in a combined group of former and
current smokers. IPF is the most common form
of idiopathic ILD, manifesting in the 6th -7
th
decades with a slight male predominance [8].
PFTs usually demonstrate a restrictive defect
with reduced lung volumes and diffusing
capacity [7]. The typical chest radiograph in IPF
shows bilateral basal and peripheral reticular
opacities. Progressive fibrosis leads to a
reduction in lung volumes and honeycombing.
Typical high resolution CT features allowing
confident diagnosis are irregular reticular
opacities, traction bronchiectasis, and
honeycombing in a basal peripheral and
subpleural distribution.
Identifying and determining the cause of
interstitial lung disease can be challenging. CT is
the key to, and sometimes the first step in, the
diagnosis of ILD’s. CT scanners use a computer
to combine X-ray images taken from many
different angles to produce cross-sectional
images of internal structures. A high-resolution
CT scan can be particularly helpful in
differentiating various patterns of smoking
related interstitial lung diseases, determining the
extent of lung damage caused by interstitial lung
disease. It can show details of the fibrosis, which
can be helpful in narrowing the diagnosis.
Materials and methods
This study was conducted in the Department of
Radio-Diagnosis at NRI General Hospital,
Chinakakani, Guntur, in 63 patients with
smoking history referred for HRCT with
symptoms of progressive dyspnoea and cough.
The duration of study was from December 2015
to October 2017. 63 patients with smoking
history referred for HRCT with symptoms of
progressive dyspnoea, cough. Descriptive
observational study was performed.
Inclusion criteria
Smokers with progressive dyspnoea and
cough
Age range 30 - 90 years.
Exclusion criteria
Non smokers
Age less than 30 years.
Study parameters being monitored
Incidence of various pathologies among
the sample of study.
Percentage distribution of sex among
various pathologies.
Percentage distribution of age group
among various pathologies.
Brief procedure
Patients clinically with history of smoking and
with progressive dyspnoea, cough HRCT
Chest examination with desired protocol (A)
Clinical diagnosis of cause for progressive
Sreedevi Meka, D Ankamma Rao. Role of HRCT in Smoking Related Interstitial Lung Diseases. IAIM, 2019; 6(8): 78-94.
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dyspnea, cough; (B) Imaging findings
Statistical analysis Conclusion.
Examination technique
A CT scan examination was performed using GE
Light Speed Multislice 4 channels present our
radiology department. The examination was done
in supine position. A scout was taken with kV
120 and mA 120, then helical scanning was done
in caudo-cranial direction to minimize respiration
artifacts, using detector row 4, helical thickness
1.25, pitch 1.5:1, speed (mm/rot) 7.5, Detector
configuration 4 · 1.25, beam collimation 5.00
mm, interval 1.00, gantry tilt 0.0, FOV depends
on the patients’ body build, but is about 35 cm,
kV 120–140, mA 120–160, total exposure time
about 16 s during breath hold in inspiration. The
images acquired were sent to a separate
workstation to be processed, manipulated and
reconstructed. Reconstruction of the images was
done using reconstruction software available at
the workstation to attain HRCT axial, coronal
and sagittal images. Also mediastinal window
images were done for each case. Various
imaging parameters were considered which
include:
Interlobular septal thickening
Honey combing
Centrilobular nodules
Centrilobular Emphysema
Bronchiectasis
Cystic lesions
Centrilobular Emphysema
Ground glass opacities
Reticular Lesions
Results
The present study was a prospective study
carried out in the Department of Radio diagnosis,
NRI Medical College, to analyze clinically
suspected smoking related interstitial lung
diseases using HRCT and comparing its efficacy
and significance in diagnosing and characterizing
various HRCT patterns. The present study
sample included 63 patients who were clinically
suspected have smoking related interstitial lung
disease (Table – 1 to 12, Case 1 to 8).
Table - 1: Percentage Distribution of Age
Among Patients Studied.
Table - 2: Percentage Distribution of Gender
Among Patients Studied.
Table - 3: Percentage Distribution of Total
Cases.
Table - 4: Percentage Distribution of Smoking
Related Interstitial Lung Diseases.
Sreedevi Meka, D Ankamma Rao. Role of HRCT in Smoking Related Interstitial Lung Diseases. IAIM, 2019; 6(8): 78-94.
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Table - 5: Frequency of HRCT Findings in Total
6 Respiratory Bronchiolitis Cases.
Table - 6: Percentage Distribution of Gender
predominance in total 6 cases of Respiratory
Bronchiolitis.
Table - 7: Percentage Distribution of HRCT
Findings in Total 2 Cases of Desquamative
Interstitial Pneumonia.
Table - 8: Percentage Distribution of Gender
Predilection In Desquamative Interstitial
Pneumonia.
DISCUSSION
Cigarette smoking is a recognized risk factor for
the development of interstitial lung disease
(ILD). There is strong evidence supporting a
causal role for cigarette smoking in the
development of respiratory bronchiolitis ILD
(RB-ILD), Desquamative interstitial pneumonitis
(DIP), and pulmonary Langerhans cell
Histiocytosis (PLCH). In addition, former and
current smokers may be at increased risk for
developing idiopathic pulmonary fibrosis (IPF).
The combination of lower lung fibrosis and upper
lung emphysema is being increasingly
recognized as a distinct clinical entity in
smokers. High-resolution computed tomography
is sensitive for the detection and characterization
of ILD and may allow recognition and
classification of the smoking related ILDs (SR-
ILDs) into distinct individual entities [7]. High
resolution CT is the imaging modality of choice
in patients with suspected smoking-related
interstitial lung disease [11]. This is a
prospective study carried out in NRI General
Hospital, in 63 patients who are suspected to
have smoking related interstitial lung disease.
Our study was planned to recognize the different
interstitial lung diseases related to cigarette
smoking with the ratio of eachpathology, the
incidence and the ability of HRCT to properly
diagnose different lesions effectively.
Table - 9: Frequency of HRCT Findings in
Idiopathic Pulmonary Fibrosis.
Table – 10: Percentage Distribution of Gender
Predilection In Idiopathic Pulmonary Fibrosis.
Out of total 63 cases of the present study, most
common age group of presentation was in three
Sreedevi Meka, D Ankamma Rao. Role of HRCT in Smoking Related Interstitial Lung Diseases. IAIM, 2019; 6(8): 78-94.
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peaks. First peak was between 60-70 years of age
(35%). Second and third peaks were in between
50-60 and 70-80 years (22%). 16% of cases were
in between 40-50 years. 3% were between 30-40
years and 2% between 80-90 years. In present
study 76% of cases were males and 24% were
females.
Table - 11: Frequency of HRCT Findings in
Langerhans Cell Histiocytosis.
Table - 12: Frequency of Gender Predominance
in Langerhans Cell Histiocytosis.
Out of 63 patients, 70% were negative cases,
16% cases were idiopathic Pulmonary Fibrosis,
10% cases were Respiratory Bronchiolitis, 3%
cases were Desquamative Interstitial Pneumonia,
1% cases were Langerhans Cell Histiocytosis.
Out of total 18 positive cases, 33% cases were
respiratory bronchiolitis, 11% cases were
Desquamative Interstitial Pneumonia, 56% cases
were Idiopathic Pulmonary Fibrosis, 0% cases
were Langerhans Cell Histiocytosis.
According to the literature, RB-ILD usually
affects current smokers of 30-40 years of age.
There is a slight male predominance. Mild cough
and dyspnea are the most common presenting
symptoms. Inspiratory crackles are present in
one- half of patients, and digital clubbing is rare
[5]. PFT results may be normal or show a mixed
obstructive-restrictive pattern. Chest radiographs
show diffuse, fine reticular or reticulonodular
opacities in over two-thirds of the patients with
RB -ILD. Ground-glass pattern may be the
predominant abnormality in some patients [5].
Few studies also report normal chest radiographs
in up to 28% cases.
In HRCT, respiratory bronchiolitis-associated
interstitial lung disease often manifests with
centrilobular ground-glass nodules, thickening of
central and peripheral airways with associated
centrilobular emphysema and air trapping on
HRCT. These findings appear predominantly in
the upper lobes [9, 10].
According to Attili, et al. [7], the most common
high-resolution CT findings in RB-ILD are
centrilobular nodules, ground-glass opacities,
and thickening of the bronchial walls, which
predominate in the upper lobes. Upper lobe
emphysema is also commonly present. A small
percentage of patients have a reticular pattern
due to fibrosis in the absence of honeycombing
and traction bronchiectasis [7]..
Out of our 6 smoker patients diagnosed as RB-
ILD had an age range of 44-67 years (mean age
55 years ± 5). Their main presenting symptom
was progressive dyspnea. General and chest
examinations revealed no significant
abnormality. Blood gases were slightly impaired
in all patients. All patients had mild restrictive
pulmonary function changes. Three of the
patients only with centrilobular emphysema had
associated mild obstructive PFT changes. HRCT
showed hyper inflated upper lobes and all six of
the patients have typical changes of
predominantly upper lobar centrilobular nodules.
Three patients had also upper lobar faint ground
glass opacities. Four had associated upper lobar
centrilobular emphysema. One patient had small
reticular lesions. None of our cases showed
traction bronchiectasis or bronchiolectasis. Also,
none of our patients had fibrosis.
On Imaging YoussriahYahiaSabriet al. reported
In 25 patients (n = 25, 62.5%) (Age range 32–61
years, mean age 47 years ± 5) HRCT showed
predominantly upper lobar hyperinflation with
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centrilobular nodules and peribronchial
thickening, 16 of whom had also upper lobar
faint ground glass opacities and 9 of whom had
associated upper lobar centrilobular emphysema.
On Imaging in present study, in 6 patients (n=6,
10%) (age-range 44-67 years, mean age 59 years
± 5). HRCT showed predominantly upper lobar
hyperinflation with centrilobular nodules, 3 of
them have upper lobar faint ground glass
opacities, 4 patients have associated upper lobar
centrilobular emphysema
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Desquamative interstitial pneumonia
Although the term Desquamative interstitial
pneumonitis has been retained in the consensus
classification of IIPs, it is considered a
misnomer, as the predominant pathologic feature
is the intraalveolar accumulation of pigmented
macrophages and not desquamation of epithelial
cells as previously thought. The condition
represents the end spectrum of RB-ILD with
similar pathologic findings and an almost
invariable association with smoking. DIP affects
cigarette smokers in their 4th or 5
th decades.
Males are affected nearly twice as often as
females.
Dyspnea and dry cough are the most common
presenting symptoms, and the onset is usually
insidious. Inspiratory crackles are heard in 60%
of patients, and digital clubbing occurs in nearly
one-half of patients. The most common and
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striking PFT abnormality is marked reduction in
diffusing capacity, with reductions of 50% or
more being common. Restrictive defects are also
common. Patients with advanced disease may
have hypoxemia at rest or with exertion.
Radiographically, lung volume appears reduced
unless there is a co-existing obstructive airway
disease such as in smokers with emphysema.
Bibasilar opacities of hazy, ground-glass
appearance are present in about one quarter of
patients. The predominant abnormality at high-
resolution CT in patients with DIP is ground-
glass opacity, which may be peripheral, patchy,
or diffuse in distribution. A peripheral sub
pleural and basal predominance of ground-glass
opacity is most commonly seen. Honeycombing
is uncommon. Coexistent emphysema may be
present [7]. .
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Koyama, et al. [11] and Lynch, et al. [22] stated
that the abnormality has a lower-zone and
peripheral distribution in the majority of cases.
Irregular linear opacities and a reticular pattern
are frequent but are limited in extent and are
usually confined to the lung bases.
Honeycombing is uncommon, but well defined
cysts may occur within the areas of ground-glass
opacification. The cysts are usually round, thin-
walled, and less than 2 cm in diameter. The
ground glass opacification usually regresses with
treatment. Progression of ground glass
opacification to a reticular pattern occurs
infrequently (<20% of cases).
Present study involved two patients with HRCT
changes suggestive of DIP. One patient is male
and other is female, age range 50-80 years-old.
All of the patients had upper limb clubbing, bi-
basal crepitation on auscultation, mixed PFT
changes of obstructive and restrictive types and
impaired blood gases.
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HRCT showed bilateral predominantly lower
lobar ground glass opacities in all of the patients.
This was not associated with any cysts .One
patient (50% of the cases) showed sub pleural
prominent interlobular septae with mild traction
bronchiectasis and traction bronchiolectasis.
None of the patient showed honeycombing or
centrilobular emphysema. On Imaging Youssriah
Yahia Sabri, et al. [21] reported in eight patients
(n = 8, 20%), (32–82 years-old, mean age 63
years± 5). 8 patients had Bilateral lower lobar
subpleural ground glass opacification,3 patients
had small cysts, 5 patients had upper lobar
centrilobular emphysema and 3 patients had
bilateral predominantly lower lobar subpleural
prominent interlobular septae with traction
bronchiectasis and traction bronchiolectasis,
associated with multiple cysts results were all
diagnostic of DIP changes.
On Imaging in present study in two patients
(n=2, 3%),(50-80 years old, mean age 65 years ±
Sreedevi Meka, D Ankamma Rao. Role of HRCT in Smoking Related Interstitial Lung Diseases. IAIM, 2019; 6(8): 78-94.
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5), 2 patients have Bilateral lower lobar
subpleural ground glass opacification and 1
patient have bilateral predominantly lower lobar
subpleural prominent interlobular septae.
Idiopathic pulmonary fibrosis
Epidemiologic studies have suggested that there
is some relationship between smoking and
idiopathic pulmonary fibrosis, the clinical entity
associated with the pathologic diagnosis of usual
interstitial pneumonia (UIP), this association is
less strong than for PLCH, DIP, and RB-ILD [3,
5]. IPF is the most common form of idiopathic
ILD, manifesting in the 6th – 7
th decade with a
slight male predominance.
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Clinical features include gradually progressing
dyspnea, chronic cough, and bibasilar Inspiratory
crackles. Digital clubbing is seen in
approximately two thirds of patients. PFTs
usually demonstrate a restrictive defect [7, 8].
Chest radiographs demonstrates bilateral
reticular or reticulonodular opacities with small
lung volumes [9]. There is a lower lung zone and
peripheral predominance in the distribution of
these infiltrates.
High-resolution CT findings consist of
honeycombing, traction bronchiectasis and intra
lobular interstitial thickening with sub pleural
and lower lung predominance [6]. When these
HRCT features are present in a proper clinical
context, the diagnosis of IPF is correct in 85%-
90% of patients.
10 of our patients have HRCT pattern of
Idiopathic Pulmonary Fibrosis, age range
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between 41-75 years, with female
preponderance. HRCT features showed bilateral
predominantly lower lobar sub pleural prominent
interlobular septae with traction bronchiectasis
and traction bronchiolectasis and areas of
honeycombing. Some of the patients (30%)
patients had associated upper lobar changes of
centrilobular emphysema.
On Imaging Youssriah Yahia Sabri, et al. [21]
reported six patients (n = 6, 15%) (32–66 years,
mean age 54 year ± 5). HRCT showed bilateral
predominantly lower lobar sub pleural prominent
interlobular septae with traction bronchiectasis
and traction bronchiolectasis and areas of
honeycombing. All those patients had associated
upper lobar changes of centrilobular emphysema.
On Imaging In present study in ten patients
(n=10, 16%), (41-75 years, mean age 62 years ±
Sreedevi Meka, D Ankamma Rao. Role of HRCT in Smoking Related Interstitial Lung Diseases. IAIM, 2019; 6(8): 78-94.
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5), 6 patients had bilateral predominantly lower
lobar subpleural prominent interlobular septae,
10 patients had traction bronchiectasis, 10
patients had areas of honeycombing, 5 patients
had reticular opacities and 3 patients had
associated upper lobar changes of centrilobular
emphysema.
Langerhan’s cell histiocytosis
Adult pulmonary Langerhans’ cell histiocytosisis
a rare disorder of unknown etiology that occurs
predominantly in young smokers, with an
incidence peak at 20-40 years of age. In adults,
pulmonary involvement with Langerhans’ cell
histiocytosis usually occurs as a single system
disease and is characterized by focal Langerhans’
cell granulomas infiltrating and destroying distal
bronchioles.
Typical findings on chest radiograph include
nodular or reticulonodular opacities most
prominent in the middle and upper lung zones
with sparing of the costophrenic angles. The lung
volumes are either normal or increased. As the
disease progresses, cystic changes and bullae
appear.
High-resolution computed tomography (HRCT)
of the chest is essential to the diagnosis, typically
showing a combination of nodules, cavitated
nodules, and thick and thin-walled cysts. In this
study only one patient (39 year-old) was
diagnosed as PLCH. HRCT showed marked
hyperinflation of both lung fields with total
substitution of normal lung parenchyma by
variable sized cysts. The patient had second-to-
third degree clubbing of both upper limbs,
markedly impaired pulmonary function with
mixed obstructive and restrictive types changes,
and blood gases were markedly impaired. The
HRCT findings together with the clinical and
laboratory results; all favored diagnosis of
PLCH.
On Imaging Youssriah Yahia Sabri, et al. [21]
reported one patient (30 year-old) showed
marked hyperinflation of both lung fields with
total substitution of normal lung parenchyma by
variable sized bizarre shaped cysts, features
consistent with pulmonary Langerhan’s Cell
Histiocytosis.
On Imaging in present study one patient (39
year-old) showed marked hyperinflation of both
lung fields with total substitution of normal lung
parenchyma by variable sized cysts. Cottin and
colleagues have described a ‘‘syndrome’’ of
combined emphysema and fibrosis. Their study
involved 61 patients; all smokers, with a mean
age of 65 years. All had PFT changes. They
named the syndrome ‘combined pulmonary
fibrosis and emphysema (CPFE)’. The
combination of emphysema in the upper lobes
and fibrosis in the lower lobes (CPFE) is being
increasingly recognized as a distinct entity in
smokers. Patients are almost exclusively men in
their 6th and 7
th decades. Lung volumes are
relatively preserved despite markedly impaired
diffusion capacity and hypoxemia during
exercise. Honeycombing, reticular opacities, and
traction bronchiectasis are the most frequent
findings at high resolution CT in the lower lungs,
while the upper lungs exhibit paraseptal and
centrilobular emphysema [7]. In some cases of
CPFE, emphysema and fibrosis may co-occur in
the same area of the lung. There is a high
prevalence of pulmonary hypertension in CPFE,
and this is a critical determinant of prognosis.
Median survival is reported to be6.1 years, better
than in patients with IPF alone but worse than
expected for emphysema in the absence of
fibrosis. None of our cases however had
pulmonary hypertension. In the present study,
there are 0% cases of combined pulmonary
fibrosis and emphysema
Conclusion
In the appropriate clinical evaluation and in the
presence of typical findings, high -resolution CT
plays an essential role in evaluation and definite
diagnosis of SR-ILD, and this may obviate
further testing. However, lung biopsy may be
needed when the high-resolution CT are
relatively non-specific or when a confident
definitive diagnosis is needed.
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The effects of cigarette smoking on the
development of interstitial lung diseases are
poorly understood. Due to rarity of some of these
interstitial lung diseases, it is difficult to firmly
establish a direct causative role for smoking in
the pathogenesis of these diseases. Nonetheless,
available epidemiological data suggest that
smoking is causally related to the development of
certain interstitial lung diseases, including
RBILD, DIP and PLCH. The preponderance of
smokers has been consistently observed in the
reported case series of patients with these
disorders. In these patients smoking cessation
may prove to be the most important and effective
therapeutic option and should be strongly
encouraged.
The role of smoking in the pathogenesis of IPF is
controversial. Cigarrette smoking appears to
increase the risk of development of IPF, but there
is no convincing evidence that smoking directly
leads to development of IPF.
We can conclude from this study that HRCT is
highly recommended for diagnosing and follow
up of smoking related interstitial lung disease
and is considered to be the best diagnostic
modality.
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